From d6fb43adc15fe68061a5fe78e5423896a081acdb Mon Sep 17 00:00:00 2001
From: futile <git@futile.eu>
Date: Mon, 30 Dec 2024 18:06:33 +0000
Subject: [PATCH] implement r/w of process memory

---
 Cargo.toml             |  1 +
 src/error.rs           |  2 ++
 src/process/handle.rs  |  2 +-
 src/process/memory.rs  | 51 ++++++++++++++++++++++++++++++++++++++
 src/process/mod.rs     |  1 +
 src/process/process.rs | 56 +++++++++++++++++++++++++++++++++++-------
 6 files changed, 103 insertions(+), 10 deletions(-)
 create mode 100644 src/process/memory.rs

diff --git a/Cargo.toml b/Cargo.toml
index ba81461..c808abb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,4 +14,5 @@ features = [
     "Win32_Foundation",
     "Win32_System_Threading",
     "Win32_System_Diagnostics_ToolHelp",
+    "Win32_System_Diagnostics_Debug"
 ]
diff --git a/src/error.rs b/src/error.rs
index 28f31ef..eb206bb 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -10,4 +10,6 @@ pub enum Error {
     SnapshotError(String),
     #[error("failed to convert integer")]
     IntegerConversionError(#[from] std::num::TryFromIntError),
+    #[error("failed to access process memory")]
+    MemoryError(String),
 }
diff --git a/src/process/handle.rs b/src/process/handle.rs
index d210f58..b55c8a7 100644
--- a/src/process/handle.rs
+++ b/src/process/handle.rs
@@ -5,7 +5,7 @@ use windows::Win32::System::Threading::{
     OpenProcess, PROCESS_ALL_ACCESS, PROCESS_VM_READ, PROCESS_VM_WRITE,
 };
 
-#[derive(Debug, Default)]
+#[derive(Debug, Default, Clone)]
 pub struct Handle(pub HANDLE);
 
 impl Deref for Handle {
diff --git a/src/process/memory.rs b/src/process/memory.rs
new file mode 100644
index 0000000..2a37711
--- /dev/null
+++ b/src/process/memory.rs
@@ -0,0 +1,51 @@
+use super::handle::Handle;
+
+use std::ffi::c_void;
+
+use windows::Win32::System::Diagnostics::Debug::{ReadProcessMemory, WriteProcessMemory};
+
+pub fn read_process_memory<T>(
+    handle: &Handle,
+    address: usize,
+    value: &mut T,
+) -> Result<(), crate::Error> {
+    unsafe {
+        match ReadProcessMemory(
+            handle.0,
+            address as *const c_void,
+            value as *mut T as *mut c_void,
+            size_of::<T>(),
+            None,
+        ) {
+            Ok(()) => return Ok(()),
+            Err(why) => {
+                return Err(crate::Error::MemoryError(format!(
+                    "failed to read memory: {why}"
+                )));
+            }
+        };
+    }
+}
+
+pub fn write_process_memory<T>(
+    handle: &Handle,
+    address: usize,
+    value: &mut T,
+) -> Result<(), crate::Error> {
+    unsafe {
+        match WriteProcessMemory(
+            handle.0,
+            address as *const c_void,
+            value as *mut T as *mut c_void,
+            size_of::<T>(),
+            None,
+        ) {
+            Ok(()) => return Ok(()),
+            Err(why) => {
+                return Err(crate::Error::MemoryError(format!(
+                    "failed to write memory: {why}"
+                )));
+            }
+        };
+    }
+}
diff --git a/src/process/mod.rs b/src/process/mod.rs
index 1d31196..86f55bd 100644
--- a/src/process/mod.rs
+++ b/src/process/mod.rs
@@ -1,4 +1,5 @@
 mod handle;
+mod memory;
 mod process;
 mod snapshot;
 
diff --git a/src/process/process.rs b/src/process/process.rs
index d72f0d9..988e773 100644
--- a/src/process/process.rs
+++ b/src/process/process.rs
@@ -1,16 +1,22 @@
-use super::{handle::Handle, snapshot};
+use super::{
+    handle::Handle,
+    memory::{read_process_memory, write_process_memory},
+    snapshot,
+};
 
 use derive_more::derive::Display;
 
-#[allow(dead_code)]
-#[derive(Debug, Default)]
+#[derive(Debug, Default, Clone)]
 pub struct Process {
-    name: String,
-    id: u32,
-    base_address: usize,
-    handle: Handle,
+    pub name: String,
+    pub id: u32,
+    pub base_address: usize,
+    pub handle: Handle,
 }
 
+unsafe impl Send for Process {}
+unsafe impl Sync for Process {}
+
 #[derive(Display)]
 pub enum Identifier {
     Id(u32),
@@ -32,12 +38,13 @@ impl Process {
                 "failed to find a process with identifier `{identifier}`",
             )));
         };
-        let process = Self {
+        let mut process = Self {
             name: snapshot.name,
             id: snapshot.id,
             base_address: 0,
             handle: Handle::from_pid(snapshot.id)?,
         };
+        process.base_address = process.module(&process.name)?.base_address;
         Ok(process)
     }
 
@@ -50,7 +57,6 @@ impl Process {
     }
 
     pub fn module(&self, name: &str) -> Result<snapshot::Module, crate::Error> {
-        dbg!(snapshot::Module::get_modules(self.id)?);
         let Some(module) = snapshot::Module::get_modules(self.id)?
             .into_iter()
             .find(|snapshot| snapshot.name == name)
@@ -61,4 +67,36 @@ impl Process {
         };
         Ok(module)
     }
+
+    pub fn read_mem<T: Default>(&self, address: usize) -> Result<T, crate::Error> {
+        let mut value = Default::default();
+        read_process_memory(&self.handle, address, &mut value)?;
+        Ok(value)
+    }
+
+    pub fn read_mem_from_ptr_chain<T: Default>(&self, chain: &[usize]) -> Result<T, crate::Error> {
+        let mut chain = chain.to_vec();
+        let mut address = chain.remove(0);
+        while chain.len() > 1 {
+            address += chain.remove(0);
+            address = self.read_mem(address)?;
+        }
+        let value = self.read_mem(address + chain.remove(0))?;
+        Ok(value)
+    }
+
+    pub fn get_addr_from_ptr_chain(&self, chain: &[usize]) -> Result<usize, crate::Error> {
+        let mut chain = chain.to_vec();
+        let mut address = chain.remove(0);
+        while chain.len() > 1 {
+            address += chain.remove(0);
+            address = self.read_mem(address)?;
+        }
+        Ok(address + chain.remove(0))
+    }
+
+    pub fn write_mem<T: Default>(&self, address: usize, mut value: T) -> Result<(), crate::Error> {
+        write_process_memory(&self.handle, address, &mut value)?;
+        Ok(())
+    }
 }